Polyamide resins with good toughness properties

Abstract

Disclosed is a novel class of linear segmented non-elastomeric thermoplastic polyesteramides. The polymers are easily obtained by reacting a carboxylic acid-terminated prepolymer (derived by reacting at least a two-molar proportion of a dicarboxylic acid with a polymeric diol of molecular weight 400 to 6000), a dicarboxylic acid, and a diisocyanate. The polymers so obtained have nylon-like properties, particularly nylon 11 or 12, but are characterized by superior high temperature properties therefrom. At the same time, they have excellent toughness and very low water absorption characteristics.

What is claimed is: 
     
       1. A linear segmented non-elastomeric thermoplastic polyesteramide having an elongation not beyond 150 percent and characterized by a recurring unit of the formula ##STR4## wherein R is selected from the group consisting of alkylene, cycloalkylene, and arylene, A is the residue of a polymeric diol HOAOH having a molecular weight from about 400 to about 6000, B is the residue of a dicarboxylic acid HOOC--B--COOH selected from the class consisting of aliphatic dicarboxylic acids having from 6 to 14 carbon atoms, inclusive, isophthalic and terephthalic acids, m has a mean value of less than 1 and greater than 0, D is the residue of a dicarboxylic acid HOOC--D--COOH such that the melt temperature of the hard segment derived therefrom is not greater than 325° C., and y has an average value of from about 11 to about 40. 
     
     
       2. A polyesteramide according to claim 1 wherein R is arylene. 
     
     
       3. A polyesteramide according to claim 1 wherein A is the residue of a polyester glycol. 
     
     
       4. A polyesteramide according to claim 1 wherein B is the residue of an aliphatic dicarboxylic acid having from 6 to 14 carbon atoms, inclusive. 
     
     
       5. A polyesteramide according to claim 1 wherein D is the residue of an aliphatic dicarboxylic acid. 
     
     
       6. A polyesteramide according to claim 1 wherein R is 4,4'-methylenebis(phenylene), A is the residue of a polyester glycol having a molecular weight of from about 1000 to 3000, B is the residue of an aliphatic dicarboxylic acid having from 6 to 14 carbon atoms, inclusive, D is the residue of an aliphatic dicarboxylic acid, and y has an average value of from about 11 to 40. 
     
     
       7. A polyesteramide according to claim 6 wherein D represents the residue from azelaic acid. 
     
     
       8. A polyesteramide according to claim 7 wherein A and B are the residues of a polybutylene azelate glycol and azelaic acid respectively. 
     
     
       9. A polyesteramide according to claim 7 wherein A and B are the residues of a polyhexylene adipate glycol and adipic acid respectively. 
     
     
       10. A polyesteramide according to claim 7 wherein A and B are the residues of a polyhexylene azelate glycol and azelaic acid respectively. 
     
     
       11. A molded article of a polyesteramide according to claim 1.